Pre-engraved projectiles and gun for firing same



Juhe 30, 1959 F, R. QMPSON 2,892,408

PRE-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME Original Filed June 14.1951 4 Sheets-Sheet 1 IN V EN TOR.

WKW 2233 fdJQW2P Frank R- Simpson I June 30, 1959 R. SIMPSON 2,892,408

PRES-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME Original Filed June14. 1951 4 Sheets-Sheet 2 a r-ark R- Sim scn-L flmimvd 4 y awoa VQQMJune 30, 1959 F. R. SIMPSON 2,892,403

FEE-ENGRAVED PROJECTILES AND Gun FOR FIRING SAME Original Filed June 14,1951 r 4 Sheets-Sheet 5 r INVENTOR. Frank 11 Simpson BYWEJAIAFM June 30,1959 F. R. SIMPSON 2,892,408

PRES-ENGRAVED PROJECTILES AND GUN FOR F'IRING SAME Original Filed June14, 1951 4 Sheets-Sheet 4 E IN V EN TOR.

Y m Frank R,SHTIFSDTI 20 9m. MM

United S PRE-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME Frank R.Simpson, Upper Darhy, Pa., assignor to the United States of America asrepresented by the Secretary of the Army 2 Claims. (Cl. 102-38) Thisinvention relates to pre-engraved ammunition for use with rifled guns.In the usual fixed round of ammunition, the projectile has a relativelynarrow soft metal driving band extending thereabout and rigidly fixedtherewith. This band has an outer diameter substantially equal to twicethe radial distance from the bore axis of the barrel to the bottom ofthe grooves of the rifiing so that as the projectile is driven along thebarrel, its driving band is scored or engraved by the riding of thebarrel and the projectile is constrained to follow the helical riflingand thereby to acquire the necessary stabilizing spin.

The present invention contemplates the use of fixed ammunition orcartridges the projectiles or bullets whereof are pre-engraved, that is,provided with helical splines which initially fit smoothly between thelands of the barrel rifling and create a minimum of friction with thebarrel surface, while effecting a substantially gas-tight relationtherewith. In an obvious manner, such projectiles reduce wear andfriction, increase muzzle velocity for the same propelling charge andincrease the useful life of the barrel.

While having great advantages, the use of pre-engraved projectiles inrapid-fire guns, requires that each cartridge be in such a rotationalposition at the instant it is rammed into the breech, that-the splineson its bullet will register or mesh accurately with the grooves of therifling. Otherwise jamming and interference may occur between theengraved projectile and lands of the rifling and impair the operation ofthe gun.

The foregoing considerations make it desirable that each cartridge befed to the breech of the gun, with its projectile positively positionedand held in the aforesaid rotational position; and in order to efiectthis function, I

propose to form the base of each cartridge case with indexing means suchas a centrally offset notch, groove or lug which will cooperate with thebelt or clip as well as with the loading mechanism of the gun, to feedeach cartridge into the gun-and load it into the breech, in properrotational position. Then when each cartridge is assembled with itspre-engraved bullet so that its splines beara certain or predeterminedangular relation with the aforesaid indexing means of the cartridgecase, proper loading of each cartridge is assured and the benefits andadvantages of pre-engraved ammunition are fully exploited.

It is the object of the present invention to provide a clip particularlyadapted to hold several rounds of ammunition in side-by-side contactingrelation so that each round is held in the desired fixed rotationalposition until ates Patent nism and tray of a 40 mm. automatic gun, withmeans cooperating with the cartridge generally and particularly with theaforesaid indexing means of its case, to positively control therotational position of the cartridge from the time it leaves its clipuntil it is rammed into the breech with the splines upon its bullet inproper meshing relation with the rifling of the barrel.

Another object is to provide a system or mechanism wherein therotational position of the cartridge and its indexing means ispositively controlled from the time it is loaded into its clip untilrammed into the breech of the gun.

Other objects and advantages will be apparent after a study of thefollowing detailed description in connection with the accompanyingdrawing.

In the drawing:

Figure 1 is a side elevation of a clip holding four cartridges.

Figure 2 is an end elevation of the clip of Figure l with one cartridgeremoved.

Figure 3 is a cross-section to an enlarged scale, taken upon-the line33, Figure 2.

Figure 4 is a cross-sectional view of a clip and cartridge in the loaderof a 40 mm. automatic gun, taken upon line 4-4, Figure 11, and showingthe way in which the cartridges are released from the clip as they arefed downwardly with respect to the loader.

Figure 5 is an end view of a cartridge provided with one type ofindexing means.

Figure 6 is an end view of a cartridge provided with a second type ofindexing means.

Figure 7 is a sectional view, taken in a vertical axial plane, of a 40mm. automatic gun and showing portions of the loader and cartridge tray,with means to positively guide the lowermost cartridge into the tray infixed predetermined rotational position.

Figure 8 is a perspective view of the loading tray show ing alongitudinal guide rail thereon for guiding the cartridges in axialtranslation only, during ramming.

Figure 9 is an end view of the loading tray and a portion of the loader,showing the guide rail in end elevation and a latch in the loader whichmay be used, if desired, to hold each cartridge with its indexing notchfitting over and about the guide rail during the initial stage oframming. L

Figure 10 is a perspective view of the rear portions of the automaticloader with a clip of ammunition therein, together with alportion of theloading tray.

Figure 11 is a sectional view taken in a vertical plane indicated byline 1111, Figure 10.

Figure 12 is a perspective view'showing the feed rollers andindexingmeans of a standard 40 mm. automatic gun.

Figure 13 is a vertical section through a portion of the gun showing aspecial attachment for guiding a round of ammunitionin fixed rotationalposition from the time it leaves the clip until it is deposited by thefeed rollers upon the loading tray.. In this figure a round has justbegun its downward movement from clip to tray. 7

Figure 14 is a. view corresponding-to Figure 13 but showing how theattachment is released from the-round in response to, depositing of theround upon the tray.

Figure 15 is a view corresponding to Figures 13 and 14 but showing theposition of the attachment forming a partv of the invention when anempty cartridge case is ejected in the direction of the arrow.

Figure 16 is an explodedview of the detent and spring forming portionsof the aforesaid attachment; and

Figures 17 and 18 are views showing the latch structure in detail.

Referring in detail to the drawing, 1 indentifies in general a clipadapted to hold f o ur rounds of cartridges and comprising a channelelement 2' generally U-shaped in cross-section and having four arcuatenotches in its upstanding sides, as indicated at 3, Figure 2. As shownat 4, upon Figure 3, one side wall of the channel element is offsetinwardly toward the other side wall, whereby to form a rim or ledge of aminimum depth substantially equal to the width of radial dimension ofthe flange of the cartridge head. As seen in Figure 1, the clip isslightly curved longitudinally on radii corresponding to those of theautomatic loader guides, whereby adjacent rounds remain in contact attheir rims as well as at a point near the forward ends of the cartridgecases. See Figure 7.

t each of four points along its length, corresponding to its four mostnarrow dimensions, the clip is provided with a non-circular rod 5slidably mounted for longitudinal movement and urged to the right, asviewed in Figure 3, by a spring 6 acting between the wall of the clipand a flange 5a fixed to the rod. In the position shown, the inner endof the rod projects from the clip so that, when forced inwardly againstthe action of spring 6, a clamp member 7 rigidly attached to the otherend of the rod, is moved rearwardly away from the clip to release therim of the cartridge case C.

The foregoing described construction is standard equipment for theautomatic loader of the Armys 40 mm. gun and per se, forms no part ofthe present invention. When this clip is used with standard ammunition,there is no necessity to locate the rounds within the clip in anyparticular rotational position. Each round is loaded simply by manualpressure. or the end of pin 5', insertion of the round into its nocthes,and release of the pin. The rounds are thus held in the position shownupon Figures 1 to 3, and, together with the clip, are slipped downwardlybetween the front and rear guides of the automatic loader for firing.

Where pre-engraved ammunition is to be .used, I propose to load eachround into its clip in the same fixed predetermined rotational positionand to include in the automatic loader of the gun itself, means by whichthe aforesaid rotational position of each round is maintained until itis rammed into the breech. For this purpose, I provide a chordal channelor groove 8 in the head of each cartridge. In addition, the circulargroove in the head of each cartridge is provided with. a pair of pins 9and 10 spaced linearly a distance equal to the width. of the clampmembers 7 and in a direction parallel to grooves or channels 8, as willbe clear from inspection of Figures 2 and 5. The pins have a projectinglength substantially equal to the depth of the circular groove 11 inwhich they are positioned so that their ends are flush with the head ofthe cartridge cases.

Figures 2, 3, 4 and 11 show that the end of each clamp member 7 isturned inwardly to form a lug fitting between the two pins and that whenthe rounds are so positioned in the clip, the grooves 8 are in alignmentin the longitudinal direction of the clip, that is, the direction ofmovement of the clip and cartridges within the automatic loader of thegun. This automatic loader includes a forward guide 12, Figure 7, havinga channel to receive and guide the noses of the splined bullets B, arear guide 13 to receive and guide the heads of the cartridge cases, andautomatic feed mechanism generally indicated at 14, but not shown indetail. In a manner subsequently described, this feed mechanism isoperated by movement of the loading tray in recoil and counterrecoil.The forward guide 12 is generally an arcuate upstanding channeled memberflaring at itstop and adapted to guide the noses of the bullets indownward movement into the gun. The rear guide as shown in Figures. 4, 7and 10, comprises a channeled member having a backing plate and sides.and 1. r id y e ured ther opr vide. a

4 longitudinally arcuate, generally vertical channel slidably receivingthe heads of the cartridges and the clip and guiding them properly whenmoved downwardly by the feed mechanism 14 of the gun in timed relationwith the loading tray, to feed a cartridge thereonto at the properinstant during recoil.

The backing plate 15 is formed with a forwardly and vertically extendingridge 1511 which engages the heads of the cartridge within the feedingmechanism and spaces them forwardly a distance suflicient to provide aspace enabling clamp members 7 to be moved rearwardly to release thecartridges from the clip as they are moved downwardly in the loader.This release is effected by .a cam plate 18 secured to or integral with,side 17, as shown in Figure 4, and having a cam surface 18a, Figure 11,which engages the projecting ends of clip pins 5 as the clip and its.cartridges slide downwardly in the loader, and forces the clamp members7 rearwardly to thereby release-the lower cartridges from the clip. In.this way, as feed mechanism .14 is, operated,v in; response to;counterrecoil movement of the. barrel and loading tr ay, to move thecartridges, one step downwardly, the lower.- most cartridge is forcedbetween the feed rollers 21 and. 22 shown at Figure 12, and subsequentlydescribed. The. feed mechanism of the gun, as just described is of standard construction. In addition, I provide a strip or rail. 19., f xed toplate 15, spaced from. and parallel, to ridge 15a. and so positionedand. of a length suflicient to engage within the aligned grooves 8 inthecartridge heads during their downward travel in the loader and untilthey cartridges, in sequence are gripped by the heads of the ramrnerlevers. By this provision the cartridges are maintained in fixedrotational positions. from the time they are loaded into the gun withtheir clip until they are deposited in sequence upon the loading tray20.

In the gun described, the loading tray is rigidly secured to the breechring and projects rearwardly therefrom and recoils as a unit therewith.This tray has cam grooves 42 and 43 along its right and left sides, andas the barrel, breech ring and tray move forwardly in counterrecoil,feed rods having rollers at their lower ends riding in the respectivecam grooves, are moved downwardly by the grooves to move all cartridgesin the loader and their clip, down one step after the empty case of thecartridge previously fired has been ejected. A pair of laterallyshaped,longitudinally-extending. feed rollers 21 and 22 are carried by theloading mechanism for positive support of the lowermost cartridge in theloader. These rollers which are in the shape of four-pointed. starsincross section (see Figure 12) are mounted in side-by-side. fore andaft relation immediately below the lowermost cartridge in the loader.Each rod is mounted at its for ward ends for pivotal movement about arespective axis as indicated at 25 and 26, which axes are parallel,vertical and normal to the axis of rotation of the rollers, whereby theseparation of the rollers may vary. This separationis yieldinglyresisted by spring-pressed indexing plungers 27 and 28 engagingrespective star index wheels 29 and 30 each rigidly attached to arespective feed roller. The relation of the plungers, index wheels andfeed rollers is suchthat the latter are yieldingly. held in positionconjointly' forming an upwardly-facing semi-circular channel into whichthe lowermost cartridge is forced by the feed mechanism. This movementforces the feed rollers and index wheels to rotate one-quarter rotationand insures that but one cartridge may be deposited upon the feed trayforeach reciprocation thereof in recoil and counterrecoil'. The pivotalmounting-of the feed roller shafts enables the rollers to separateslightly and continuously grip a cartridge as it passes therebetween.The rollers are. nor.- mally locked in position by catch heads 31 and32: mounted upon respective spindles 33 and- 34. During counterrecoil,when the cartridgesare being depressed by. the feed mechanism to;deposit the lowermost cartridge upon. he tr y. he-.loadingtray.paw1s.;3.5 and 36,.Eigurei 8, engage and rotate thevcatch heads. Thisaction releases the feed rollers and permits them to be revolved by thecartridge in the manner previously described. When the cartridge haspassed between the feed rollers and the rollers have rotated one-quarterturn, the catch heads are returned to their normal positions by torsionsprings such as 37, shown in Figure 12 for catch 31. This again locksthe rollers in position until released by the next reciprocation of thetray.

The upper ends of the rammer levers are indicated at 38 and 39, Figure8. These levers are independently pivoted on a common rammer rod (notshown), as the gun and tray move in counterrecoil toward batteryposition. The rammer levers project upwardly through respective camslots 40 and 41 in the loading tray. These slots haveoppositely-disposed riser portions 40a and 41a each connecting straight.parallel portions at differ- 'ent transverse distances from the centrallongitudinal axis of the tray. As previouslydescribed the automatic feedmechanism is operated by rollers not shown, riding in respective camslots or channels 42 and 43 formed upon the tray 20. See Figures 7 and8. These slots have riser portions 42a and 43a, each connecting twoparallel sections, such as 42b and 42c and act to raise the feed pawlsduring recoil and then to lower them at the proper time duringcounterrecoil to effect the aforementioned downward feeding of thecartridges and to move the lowermost cartridge between feed rollers 21and 22, andto deposit it upon the tray.

Forward movement of the tray with the gun barrel in counter recoil actsto tension a rammer spring, not shown, which then acts to urge therammer arms forwardly in their slots 40 and 41. The active or riserportions 40a and 41a of slots 40 .and 41 are so positionedlongitudinally of the tray, with respect to the active portions 42a and43a of channels 42 and 43, that the upper ends of rammer levers 38 and39 are moved inwardly toward each other at the instant the feedmechanism is operated to deposit a cartridge upon the tray. At thatinstant, of course, the rim or head of the deposited cartridge iscoplanar with the rammer levers so that as "the rammer levers movetoward each other they grip the head of the cartridge between them.Atthis time the rammer levers are latched in rearwardmost position while"the gun and tray are moving in counterrecoil toward battery position.The 'breechblock ofthe gun is, of'course, fully open.

As the barrel and tray near battery position loading tray pawls 35 and36 trip the catch holding the rammer lever and arms 38 and 39 inretracted position and the now-compressed rammer spring throws the armsand the cartridge gripped between them, forwardly at extremely highspeed. As the arms move forwardly past the riser or active portion 40aof their slots, they are separated. The cartridge is released and movesforward under its own momentum into the breech. Movement of thecartridge into the breech releases the breechblock in a well-knownmanner which, on closing, fires the gun when in automatic fire.

In view of the fact that there might otherwise be a short period afterthe cartridge leaves guide strip 19 until it is gripped by rammer levers38, 39 and otherwise held in rotational position upon the tray, I haveprovided a detent mechanism which, in effect, forms a continuation ofstrip 19 and moves downwardly with the cartridge until the latter isgripped by the rammer levers.

This detent or guide mechanism comprises a plunger element 44 having ahead 44a slidably fitting a bore 45 formed in the loader frame. Theplunger is limited to reciprocation only and is urged upwardly by a coilspring 46 into the normal position shown upon Figure 15. The plungerelement has a forwardly-offset end portion 44b. This portion has itsforward vertical edge so shaped and normally positioned to form acontinuation of guide strip 19, as will be noted from Figure 15, wherebythe rotational position of the lowermost cartridge is controlled only bythe detent or guide mechanism by reason of its engagement within theindexing groove in the cartridge head.

A latch generally indentified by the numeral 47 in Figures 13, 14 and15, and shown in greater detail upon Figures 16, 17 and 18, is carriedby the lowerend of ofiset portion 44b. The latch may conveniently havethe general form shown upon Figure 16, pivoted to they plunger on atransverse axis defined by aligned holes 48 and urged into clockwiserotation as viewed in Figures 13, 14 and 15, by a leaf spring 49 havingforwardly ofiset lateral projections 49a. These projections engage therespective side walls of latch 47 and urge the same into a rotationposition wherein the nose portion 47a projects forwardly into a positionto be engaged by the rim of the lowermost cartridge, as shown by Figure15. Rotation of the latch is limited to the position shown on Figures 13and 15 by engagement between the edges of projections 47b, with the endsof a pin 50 having a press fit within a transverse bore in plunger 44.The base of the latch has rearwardly-projecting arms 470, Figure 16, toand between which there is secured an'anti-friction block 51, Figures 17and 18. This block projects below the lower edges of the arms 47c and,being rearwardly offset from the axis of holes 48 pivots the latchcounterclockwise when moved into contact with the surface of loadingtray 20.

By the construction just described, as the lowermost cartridge is forceddownwardly by the feed mechanism, in the manner previously described,its engagement with nose 47a of latch 47, causes the entire plungerelement to move downwardly as a unit with the cartridge until, whenblock 51 strikes the loading tray, the latch 47 is pivoted to removenose 47:: from the rim of the cartridge. whereupon, spring 46 causes theentire plunger element to snap back into the position shown in Figure 15wherein the forward edge of portion 44b engages within the indexinggroove 8 of the next cartridge.

It will thus be seen that the construction just described maintains eachcartridge, as his fed downwardly from the feed mechanism to the loadingtray, in fixed rotational position and acts to maintain such positionuntil the cartridge rests upon the tray and is engaged by the rammerarmsas previously described.

It is contemplatedthat the rammer levers alone may be sufiicient tomaintain the cartridge in proper rotational position upon theloadingtray until it is released therefrom by-the action of the activeor riser portions 40;: and 41a of slots 40 and 41, and thrownforwardly'at high velocity into the breech. However in addition to thegripping action of the rammer levers, I provide a guide rail 52, rigidlysecured to the loading tray longitudinally thereof and so positioned andshaped as to engage within the notch in the rim of the cartridge case,such as 8a, Figure 5. This guide rail is in the same longitudinalvertical plane as guide strip 19 so that, as the lowermost cartridge inthe loader or magazine is guided downwardly without rotation, the notchin the rim of its head fits over and engages the rail. This acts toprevent angular movement of the cartridge during the instant its rim isgripped by the rammer levers. As the guide rail extends throughout thelength of the loading tray, as shown upon Figure 8, the correct angularposition of the cartridge is maintained after it has been released byportions 40a and 41a of the cam slots as the rammer rod and its arms aremoved forwardly relatively to the tray. The cartridge is thus positivelyguided to prevent its rotation or angular movement about itslongitudinal axis from the time it is loaded into the magazine orloader, until it is rammed into the breech with the splines of itsbullet in proper registration with the rear terminals of the riflinggrooves of the barrel.

Due to the high speed with which the cartridge is rammed into thebreech, and with which the empty case is thrown rearwardly by theextractors, it is desirable to;provide some means for exerting adownward force uponthe cartridge during its forward movement with andalso relatively to, the tray, as well as during the rearward movement ofthe empty cartridge case. For this purpose, I have provided a yieldingor flexible detent 5-3, Figures 7 and 9. This detent is pivoted atoneend, as indicated at 54, Figure 9, on a longitudinal axis and isurgedinto clockwise rotation, as viewed, by. a spring 55. The .detent ispositioned on the automatic loader just beneath and forwardly of thefront cartridge guide 12 so that the nose of each cartridge just clearsthe same as it is fed downwardly onto the tray. The detent is limited indownward pivotal movement, by any suitable stop mechanism, not shown, tosubstantially the position shown upon sFigurev9. Hence, as the cartridgeis moved forwardly, the noseof its bullet passes beneath the detent andpivots the same upwardly against the force of spring 55. The detent thusexerts a downward force'upon the cartridge which prevents it frombouncingtupon the tray. As the empty cartridge case is thrown rearwardlyby the extractors, its rim again cams detent 53 slightly upwardlywhereby the empty case is held with the notch in its head fitting over:rail 52 so that the correct rotational position of the empty case ismaintained until it is clear of he gun.

When cartridges having index means of the type shown upon, Figure 6 areused, it is contemplated that the loading tray willbe provided with twospaced parallel guide rails similar to rail 52, each position to fit arespective notch.8b and 8c.in the cartridge rim, thus atfording addedprotection against axial rotation of the cartridge and empty case.

.I have thus provided a complete system particularly adapted for thevautomatic gun described wherein preengraved ammunition may be usedwithout dange? of jamming and the great benefits and advantages thereofutilized and exploited to the fullest extent. Any minor rotationalmisalignment between the cartridge and the riding at the breech will becorrected by the tapered or pointed ends of the splines upon the bullet,as indicated upon.Figure 7 and as described in my United States LettersPatent No. 2,659,262, issued November 17, 1953, wherein is disclosed andclaimed an apparatus for assemblying pre-engraved bullets in properpredetermined angular relation with respect to the indexing slot and fornotches upon the head of the cartridge case.

In the claims, the term indexing means comprehends theslot 8 or S'Masshown in.Figures 5 and 6 respectively, and at least one notch in thecartridge rim, such as 8a, Figure 5, or 8b or 8c, Figure 6. The termmeshing relation means an angular or rotational position of thecartridge with respect to the breech wherein the splines upon thepreengraved projectile of the cartridge will freely ,enter between thelands of the rifing of the barrel at the breech end thereof, by astraight axial translation of the cartridge and without any substantialrotation thereof. By -ramming position is meant a position of thecartridge rearwardly of the breech and in axialalignment with the boreof the gun whereby loading into the breech may be effected by a pureaxial translation of the cartridge. The term transverse as applied tothe groove or channel in the head of the cartridge case, means at rightangles to the central longitudinal axis of thecartridge.

Having now fully disclosed the invention, what I claim and desire tosecure by Letters Patent is:

'1. In a cartridge including a cylindrical case having a circular groovein its head and a pre-engraved projectile secured in and closing theforward end of said case, indexing means for said projectile comprisinga chordal channel in said head, and means securing said projectile inindexed position comprising a pair of engagement pins fixed in saidcircular groove and spaced in a linear direction in said groove in adirection parallel to said channel, said pins having a projecting lengthsubstantially equal to the depth of said circular groove.

2. In a fixed round of ammunition, a cylindrical case having a circulargroove in its head, said groove defining a 'rirnportion therein aprojectile having helical splines secured in and closing the forward endof said case, said splines being beveled at their forward ends thereof,indexing means for said projectile on said case comprising a centrallyoifset transverse channel in its head thereof, there being at least onenotch in said rim portion, and means for the securement of saidprojectile in indexed relation comprising a pair of engagement pinsfixed in the floor of said circular groove and spaced in a lineardirection parallel to said transverse channel and projecting to a lengthsubstantially equal to the depth of said circular groove, saidtransverse channel, said notch and said projectile, having apredetermined fixed angular relation with respect to the centrallongitudinal axis of said cylindrical case.

Cole Sept. 24, 1901 'McWhorter Mar. 3, 1953

